The Core currently provides radioimmunoassay (RIA), immunogenetic, and other basic biochemical assays performed in support of the studies carried out on the General Clinical Research Section (GCRC), as well as animal studies taking place in the laboratories of individual investigators. Over the last 5 years there has been a tremendous increase in the number of rodent mouse models created to study various aspects of types 1 and Type 2 diabetes, their complications and obesity. At the Joslin Diabetes Center there are currently at least about 68 rodent models that are being studied and 17 more are in various stages of being created. This has resulted in the obvious need for the measurement of rodent hormones and metabolites on a large scale. Assays are currently performed by individual laboratories using different kits and are not cost-effective. It is proposed to expand the current Core at Joslin to undertake measurement of the multiple hormones, metabolites and other markers of diabetes required by these animal studies. The new Specialized Assay Core (stated as Core here onwards) will be responsive to the varied requirements of investigators by providing an assay service and back-up support for experiments involving humans and animals. Furthermore, the facility will also provide advice and consultation, and if necessary develop and perform additional assays for novel hormones, metabolites and markers when required by the investigators. In a large institution such as the Joslin, there are often multiple investigators measuring similar parameters as part of their basic research or for clinical protocols. In the operation of any central assay Core, greater efficiency is created by planning and integrating facilities and personnel. This results from sharing antibodies, reagents and equipment, allows more economic use of expensive or limited materials, and provides for more focused training of junior investigators. It is proposed that all the human insulin assays (accruing from GCRC and other studies) will be performed at the BIDMC assay Core, which is equipped to handle the current number of human insulin assays performed at the Joslin. The BIDMC unit is the Core laboratory of the NIH-funded GCRC and will be able to assay human samples for insulin and thereby provide for a single center for both Joslin and BIDMC investigators. Consequently, this will free up a portion of the current time available for the technician to take on more of the DERC-related insulin assays and if time permits to focus on setting up, maintaining and running the additional different assays in the proposed Specialized Assay Core.